Sources of resistance to brown leaf spot [Drechslera oryzae (Breda de Haan) Subram. & Jain] in some wild Oryza spp.

摘要

A study was conducted to evaluate 200 accessions belonging to 14 wild Oryza species for resistance against brown leaf spot (BLS) pathogen Drechslera oryzae [Cochliobolus miyabeanus] under simulated epiphytotic conditions. In all, 13 accession were resistant, with mean BLS score of 0-3.40. Of these, 8 accessions, i.e. IRGC Nos. 100140, 100854, 100983, 102500, 102520, 104020, 104033 and 104350 belonged to Oryza glaberrima, two, i.e. IRGC Nos. 104433 and CR 100440, belonged to Oryza rufipogon while one each, i.e. CR No. 100142 and IRGC Nos. 105440 and 103303 belonged to Oryza nivara, Oryza rhizomatis and Oryza australiensis, respectively. Fifty-nine accessions were moderately resistant, with mean BLS score of 3.41-5.40. Of these, 29 belonged to Oryza glaberrima, four to Oryza rufipogon, 14 to Oryza nivara, six to Oryza longistaminata, four to Oryza australiensis with one each belonged to Oryza punctata and Oryza brachyantha. The remaining 129 accessions were susceptible with mean BLS score of >5.41.